Solar System
by Merthergirl
Summary: Sheldon and Sherlock are so alike. and yet so different. and who are there to suffer for the arguing? Lenard and John of course!
1. Chapter 1

Solar System- A Sherlock/Big Bang Theory crossover

**Pairings; Sherlock x john. Suggestions of Leonard and penny, not strong though.**

**For my friend Moriarty, for giving me the idea :D Chapter One :D**

"Sheldon, it's one in the morning. You're not still online reading all that 'science of deduction' crap are you?" Leonard yawned, rubbing his eyes and peering at the screen of Sheldon's laptop.

"It's not crap it's incredibly interesting. Why he thinks deduction counts as a science is beyond me, but the theory, methods and results are truly exceptional." Sheldon scrolled down the page and continued reading, nearing the end. Leonard sighed and went to the kitchen area before grabbing a glass of water and retreating to his room, "Go to bed, Sheldon."

"No." Sheldon said, scrolling down to the end of the last entry, where the author's contact details caught his eyes. "Hmm…"

… ^_^

"How remarkable." Sherlock exclaimed, taking a sip of his coffee, "John, pack your things. We're going to America."

"Pardon?"

… ^_^  
>"Penny, if someone comes around looking for us while we're out please can you entertain them? Sheldon's expecting two men over."<p>

"Two men?"

"Yes, Some private detective and a doctor from England. God knows why."

"Wait, Leonard, what do I do with them?"

"Make them tea or something. I don't know!" Leonard sighed, following Sheldon out to the comic book store.

Penny groaned. She had a feeling that when the men arrived Sheldon and Leonard wouldn't be back.

…. ^_^

She was right. Sherlock Holmes the CONSULTING detective and dr John Watson were sat on her sofa before she knew it. "Um can I get you something to drink?"

"Tea would be lovely thanks." John smiled, "Sorry to drop in like this."

"It's alright." Penny said, "Sheldon tends to be awkward with timings."

Sherlock peered at her dully, "How long will he be, around?"

"Hard to say. They've gone to the comic book store so could be a while if a new issue of some geeky thing is out."

"Comic book store…" Sherlock sounded slightly disappointed at such a childish thing to do.

"Yeah." Penny sat down and peered at them both curiously. Sherlock sat straight, pompously, legs folded over one another. John sat almost as straight but no where near as obnoxiously, and he smiled weakly at her, "So… was your flight okay?"  
>"It was acceptable." Sherlock smiled. John nodded, "more pleasant then usual, really."<br>"Good." Penny said, pulling the duck face that so deeply annoyed Sherlock. He shifted in his seat, sighing, and sipped the tea she gave him. he pulled a face.

"What?"

"Nothing it's just… weak." He said, putting the mug down.

John smiled apologetically at her.

**Knock Knock Knock**

"Penny."

**Knock Knock Knock**

"Penny."

**Knock knock Knock.**

"Penny."

Penny sighed and got up, opening the door, "Hello Sheldon. They're here."

"Oh good." Sheldon said, entering the room and looking at Sherlock and John. "Hello. I'm Doctor Sheldon Cooper, and this is my roommate Lenard."

"Hi." Leonard said, as Sherlock immediately began talking to Sheldon. John smiled and said hello back, instantly knowing that he and Lenard were in the boat with a difficult roommate.

**I know it was short, the next will be longer :D please review ^_^**


	2. Chapter 2

Two

**Thanks to everyone who reviewed, I wasn't expecting this to be so popular! :D I'm glad it is though :D**

"Come inside," Sheldon said, gesturing for Sherlock to cross the hall, and both proceeded to do so.

Penny peered at their retreating figures, "Um.. Leonard?"

"Yeah?"  
>"Is he… Sheldon's deal?"<p>

John gave a little exclamation, and "I hope not for your friend's sake. Sherlock's a sociopath."

Leonard laughed nervously, "Penny, would you get me a drink?" he said, hinting that she was about to make a fool of herself.

"Get it yourself." She said, not getting the hint, "You know where they are."

Leonard laughed nervously again and shoved her through into the Kitchen area, "Now."

"Fine!" she pouted and stomped away.

"Don't worry." Leonard smiled. "Sheldon's like that. I think. Well. Who the hell knows, ey?" he laughed, "With people like them."

John smiled, "Yeah. Pain in the necks, aren't they?"

"Yes!" Leonard grinned, "It's nice to talk to someone who understands! What does yours do?"

"Runs off a lot, yells at me a lot, rarely eats, doesn't understand human emotions- or at least pretends not to- and is just a general pain in the arse. Yours?"  
>"Same, can you whistle?"<p>

"No. can you?" John grinned.

Leonard just raised his eyebrows. "Why do you even ask?"

Both grinned, glanced towards the closed door and began to whistle.

"LEONARD!" Sheldon emerged, eyes aflame.

"A-alright. Sorry." Leonard said, grimacing. John chuckled, increasingly enthusiastic about this whim of a trip, after all.

….

"So this is your work?" Sherlock said, seeming pleased.

"Yes." Sheldon smiled, rubbing his hands together and looking rather eager to please, "But do tell me about your work."

"Strange." Leonard said out of the side of his mouth to John, "He loves talking about himself."

"Odd." John said musingly, "What're they up to?"

Howard, who had been staring at John for some time now, reclining on Leonard's sofa, spoke up, "So what do you do?"

"I am technically an army doctor." John said, "Well… used to be. Now I'm half GP and half Sherlock's assistant, I guess."  
>"GP? Step down, isn't it?" Howard asked. Rajj elbowed him in the ribs. "Owch. Okay, point taken."<br>"Yeah, I guess. But it's easy and-"

"The woman was pretty." Sherlock added. John glowered at him.

"Oh I will never understand that motive." Sheldon mused. Sherlock agreed. "It must be one of those social implications." Sheldon muttered, and once again, Sherlock agreed.

John, Leonard, Howard, Rajj and Penny stared in shock, eyes wide, unbelieving the scene in front of them.

"Is he… actually… agreeing with him?" Leonard choked.

John nodded, feeling numb with shock.

"Wow. What is going on?" Howard asked.

Everyone else shook their heads, watching Sherlock and Sheldon solve an equation together, not understanding what was going on, and wanting to with every fibre of their beings.

**Sorry for the delay, please review x**


	3. Chapter 3

Three

**Thank you thank you thank you to everyone who reads and reviews! Reviews for this story are all so positive and lovely and *tears up* sorry hehe, I love you all! **

***ahem* please read and review, and check out my other Sherlock and big bang theory stories :D**

It was now eleven pm, and Leonard was still shooing neighbours and friends out of the apartment. They'd all come to gawp at Sheldon making friends with someone so quickly.

The men in question were now in the kitchen, sipping coffee and discussing family.

"Have any siblings?" Sheldon asked, studying Sherlock's face. Sherlock, who had been deducing things about this fascinating man all afternoon,

"Yes. A brother. Mycroft." Sherlock said, "You?"  
>"A sister." Sheldon said. It was clear he wasn't fond of her, "Missy."<p>

"Why don't you like her?"

Sheldon groaned, "She's stupid. And whoreish and-"

"Mycroft, basically." Sherlock laughed.

John, who was in the lounge, stared with his mouth wide open, eyes wider. He'd never seen anything like it!

Leonard, who had just finished pushing Penny and Howard out, joined him, sipping his coffee and staring too, "Have you ever seen anything…." He asked, transfixed by the other two men, who were now debating over why people were so stupid in general, and the stupidest people in the world.

John turned to Leonard, wondering, "Does Sheldon have any… enemies?"

"Apart from everyone he knows?" Leonard laughed. John chuckled,

"I meant, certain ones."

"Lesley, an ex-girlfriend of mine. They're always fighting over who's smartest."

"Ah." John smiled, thinking of Moriarty.

"Yours?"

"This guy… Jim Moriarty, he's some mastermind."

Leonard laughed, "Oh dear. This is getting creepy now."

"Agreed."

For a moment they turned their attentions back to Sherlock and Sheldon.

"Why are they here?" they spoke at once.

"What's Sheldon up to?" Leonard asked, worry stretching across his face.

John swallowed, "Oh no. I bet it's something…. Scary?"

Leonard nodded, licking his lips. "Mm… you know that feeling?"

"I have it all the time." 

**Next chapter is longer, I promise :L **


	4. Chapter 4

Four

**Please review, sorry for the delay, I've been studying away :L really short chapter, at the expense of a rather long one next chapter :D**

"So you're a physicist?" John asked, smiling as he and Leonard settled down on the sofa- on Leonard's warning leaving Sheldon's spot alone- with a fresh cup of tea.

"Yes." Leonard replied, swallowing and placing his mug down, "Experimental. And yourself?"

"I used to be an army doctor." John said, "But now I'm just a GP."

"Ah. Like it?"

"It puts bread on the table."

"Doesn't Sherlock work?"

"He's a detective. But he doesn't accept payment."

"So he's a free private detective?"

John considered, "Ish. He calls himself a consultant detective. The police contact him if they're stuck."

"Oh." Leonard smiled, "Nobody wants to work with Sheldon."

"Nobody really wants to work with Sherlock either!" John laughed, "So what does Sheldon do?"

"Theoretical physics. He's a genius at it, according to himself."

John laughed once more, "Its scary how similar they are."

"I'm more worried about the outcome of this." Leonard said, frowning.

John nodded, then, looking around asked, "What do you do for fun around here?"

Leonard considered, then offered, "Star Trek?"

"Sorry?"

John, having never really watched Star Trek before, was pleasantly surprised as he and Leonard sat down and watched it. As Sheldon and Sherlock joined them, silence filled the apartment, and John started to wonder if anything bad could come from this at all.

The answer was yes. Yes it could.

**Told you it was short :3 **


	5. Chapter 5

Solar System- 5

**Hey everyone! :D Sorry for the late update!**

Penny, boiling the kettle, tied her hair into a loose ponytail and yawned, stretching. Her pyjamas lifted at the stomach, but she didn't mind because it was an unusually hot day, even for Pasadena. As she set up the mug for coffee she wondered how Leonard was coping with Sheldon and his little playmate. The coffee was good, but she found herself not being able to enjoy it. Concern for her neighbour growing as she realised that there had been no sound from the apartment across the hall, Penny decided that she'd go interrupt, just in case.

**Knock Knock**

"Good morning!" Penny exclaimed, only to jump backwards when Sherlock opened the door.

"Oh." Sherlock said, lamely, and Penny stood there in shock as he surveyed her, eyes glittering with a dull interest. "Waitress. Single. A little dependant on other people's approval. Some issues with her father."

"What the hell?" Penny's response was usual, and Sherlock smiled, "Come in."

Penny stormed past him and into John, who pulled a knowing face, "Don't let him get to you. He's just like that."

Penny was becoming creeped out by the similarities here.

"Where's Leonard?" She asked, and John smiled, "He's having a shower. Sheldon's getting the mail."

"Oh, ok." Penny smiled and then, swinging her arms and legs casually she turned to them, "So…."

Sherlock wandered off, peering at one of the physicist's boards of calculations, but John looked back brightly, interested in what she had to say. Encouraged, she began, "What's England like?"

John looked a little taken aback. "Cold, rainy, windy, the usual. I love it."

Penny smiled, bemused. Why was that a good thing? Was it? or was it English humour?

Luckily, Sheldon then re-entered the apartment, holding the mail, "Bill, bill, bill, Leonard, Leonard, me, me, me, me- me again- don't want that, bill and something for Penny."

He gave her the magazine and she grinned, "I love this!"

"What is it?" John asked, peering at the glossy cover.

"It's a food mag." She said, blushing, "It's got loads of restaurant reviews and places to go and stuff like that- there's a whole section on healthy foods, snacks and sometimes jam aha!"  
>"Does it let English people subscribe?" John asked, interested. They both began to flick through the magazine, relishing in this guilty pleasure together.<p>

Howard and Raj knocked on the door, both wielding a kite, "Hey, Sheldon, it's time to go- oh." He caught site of John, who stood, smiled and glanced at Sheldon.

"Sorry Howard, but I have some… friends over."

"Friends?" Howard asked, walking into the apartment and turning to look at John, who stepped forward, hand outstretched. Sherlock moved too, but to deduce rather than introduce. Raj followed Howard, and glanced nervously at Sherlock, who was studying him rather thoroughly.

"Howard, Raj, I would like you to meet Dr John Watson-" Sheldon began.

"A real doctor." Penny said, "Not you doctor."

"Thank you, Penny- and Sherlock Holmes, a detective."  
>"Hi." Howard said.<p>

"Insecure, both of you." Sherlock mused, before going back to the physics book he had been reading.

"Ignore him." John said, "He's always like that."  
>"No we're used to it…" Howard said, eyes still fixed on Sherlock.<p>

"So no kite flying today, gentlemen." Sheldon said, going to sit next to the detective, and they began discussing the book.

Leonard emerged from the bathroom in a towel and said, bemused, "oh, everyone's here. Great."

This would not turn out to be the worst of his troubles.

**Please review **


End file.
